Detective Inspector Brian Foster said: “I would particularly like to speak to the driver of a white coloured Saab car, who may be able to help us with our enquiries. I would appeal to them to contact police at Armagh on the non-emergency number 101.

The girl - who is understood to have been out running - was airlifted to the Royal Victoria Hospital.

A spokeswoman for the hospital tonight said the girl was in a critical condition.

The horrific smash was one of several collisions on a weekend of carnage on the roads.

Maureen Buchanan, 80, died and four others were injured in a six-vehicle smash on the M1 motorway between Moira, Co Down and Lurgan, Co Armagh on Friday evening.

The tragedy resulted in long tailbacks. Police said the delays were necessary “to carry out a full and thorough investigation”.

PSNI Assistant Chief Constable Alan Todd added: “I would firstly like to extend my condolences to the family of the woman who died following the six-vehicle road traffic collision yesterday evening.

“It is with reluctance that we close any road, particularly a motorway during Friday evening rush hour however, following any fatal road traffic collision police have an obligation to carry out a full and thorough investigation into the exact circumstances of the collision and the scene must be closed in order for that investigation to take place.”

Several drivers had a lucky escape after another six-vehicle crash on Saturday afternoon, this time on the M2.

Weather conditions were extremely poor at the time of the crash near Sandyknowes roundabout, with snow and hail hitting many parts.